<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
    <script>
      console.log(123 && 456); //456
      console.log(123 && 456 && 1 + 2); //3
      console.log(0 && 123 && 456); //0
      console.log(123 && 0 && 456); //0
      console.log("" && 123);
    </script>
  </head>
  <body></body>
</html>
